A consultant says nearly the entire 120,000-square-foot concrete open area at Big League Dreams Gilbert must be replaced because the soil beneath it was insufficiently stabilized during the baseball park’s construction in 2006-07.

But the builder, M.A. Mortenson, is disputing the extent of that work as the two sides continue a months-long negotiation over an extensive list of repairs to the stadium, which will have cost Gilbert taxpayers $53 million by the time the venue’s bonds have been paid off in 2021.

The town has requested Mortenson to correct improper water drainage, level the floors, strengthen the fire lane, remedy erosion behind the dugouts, and repair the baseball bollards, stadium seating, playground shade structure, stairs and handrails that all show decay beyond what might be reasonably expected in a structure so relatively new.

A geotechnical evaluation by Ninyo&Moore Geotechnical and Environmental Services Consultants has indicated that the structural flaws in the baseball park, such as cracks and crumbling concrete, are due to settlement and expansion of the soil underneath. The report suggests Mortenson should have considered more carefully the peculiarities of the Arizona soil when it design-built the stadium at Elliot and Power roads.

Soil movement is natural, said Lee Brush, capital projects manager in Gilbert, “but your design is supposed to take that into consideration.”

“Throughout Arizona we have very clay soil and if the soil is dry and it gets wet, it expands and you have upward movement of the concrete work. If it’s too wet and it dries you have downward movement. Or, if the soil is not compacted strong enough, the settlement of the pure weight of the concrete on top or vehicles driving over it can cause it to settle,” he said.

The contractor disputes the extent of the concrete work needed.

“At this time, Mortenson believes the amount of concrete flatwork that needs to be replaced is significantly less than the 120,000 square feet referenced. We are currently working through this and discussing options with the town of Gilbert,” Chris Norcross, vice president and general manager of Chandler-based Mortenson Construction, said in an e-mail to The Republic.

“Mortenson will stand behind its work, and the work of its subcontractors, and we are committed to making sure that the town of Gilbert receives the end product it deserves,” he added.

“Our plan is to work closely with the town and Big League Dreams to develop a detailed schedule that will minimize disruption to their daily operations. As it now stands, almost all of the usage for BLD comes after 4 p.m. on weekdays and on weekends, which would be outside of our normal project work hours,” he wrote.

In February, the town sued Mortenson Construction after an engineering analysis indicated flaws in the sports park that was opened in 2008.

In a turnkey project, Gilbert spent $43 million to build and outfit the town-owned stadium before handing it over to the operator, Big League Dreams. Out of that amount, more than $36 million was paid to Mortenson.

A few weeks after the lawsuit was filed, Mortenson began negotiating with the town on the repairs. Simultaneously, the town hired Ninyo & Moore to do a forensic geotechnical evaluation of the sports park. The company reviewed the construction-related documents and studies from 2006-07 and tested soil around the venue.

Gilbert is requesting that Mortenson should pick up the full cost of the repairs. Talks are ongoing, and the most recent meeting was a few days ago.

“We have a running list,” said Andi Welsh, assistant to the town manager. “There are some items that we have reached resolution in and there are some that need further research and more discussion.”

Another major repair issue involves the concrete pavement that is the fire lane. It was built with thinner concrete slabs than normally recommended, the town says.

“A fire lane must be able to maintain a big firetruck that weighs 85,000 pounds. Wherever there is a dedicated fire lane, there needs to be design parameters that allow an 85,000-pound vehicle to be able to drive on the surface without cracking, without causing settlement,” Brush said.

The Gilbert Fire Department and the town’s requirement was 8-inch-thick concrete over an engineered filling material to help prevent cracking. The report states that concrete thickness currently ranges between 2.5 and 5 inches.

Meanwhile, some repairs have been agreed upon.

Norcross said the town has raised several issues that are not directly connected to the original repair concerns.

“Some of these will require further discussion and we are committed to working with town leadership to better understand these additional concerns, which may be part of an expanded scope of work,” he wrote, reiterating that his company has a “genuine interest” in resolving the matter.

“Our team members are raising families all across the Valley and we are active in our communities,” Norcross wrote. “We take pride in building for our friends, neighbors and customers. This is our home.”

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